package com.mybase.app.Utils;

import android.util.Base64;

import javax.crypto.*;
import javax.crypto.spec.SecretKeySpec;
import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;

/**
 * Created by tukela on 2015/3/12.
 */
public class SecretUtil {

    /**
     * 加密
     *
     * @param content 需要加密的内容
     * @param password  加密密码
     * @return
     */
    public static byte[] encrypt(String content, String password) {
        try {
            KeyGenerator kgen = KeyGenerator.getInstance("AES");
            kgen.init(128, new SecureRandom(password.getBytes()));
            SecretKey secretKey = kgen.generateKey();
            byte[] enCodeFormat = secretKey.getEncoded();
            SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
            Cipher cipher = Cipher.getInstance("AES");// 创建密码器
            byte[] byteContent = content.getBytes("utf-8");
            cipher.init(Cipher.ENCRYPT_MODE, key);// 初始化
            byte[] result = cipher.doFinal(byteContent);
            return result; // 加密
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
        } catch (InvalidKeyException e) {
            e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (IllegalBlockSizeException e) {
            e.printStackTrace();
        } catch (BadPaddingException e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 加密
     * @param content 需要加密的内容
     * @param password  加密密码
     * @return
     */
    public static String sampleEncrypt(String content, String password) {
        byte[] result=encrypt(content,password);
        return SecretUtil.parseByte2HexStr(result);
    }

    /**
     * 另一种加密方式加密
     * 这种加密方式有两种限制
     *一、密钥必须是16位的
     *二、待加密内容的长度必须是16的倍数，如果不是16的倍数，就会异常：
     *
     * @param content 需要加密的内容
     * @param password  加密密码
     * @return
     */
    public static byte[] encrypt2(String content, String password) {
        try {
            SecretKeySpec key = new SecretKeySpec(password.getBytes(), "AES");
            Cipher cipher = Cipher.getInstance("AES/ECB/NoPadding");
            byte[] byteContent = content.getBytes("utf-8");
            cipher.init(Cipher.ENCRYPT_MODE, key);// 初始化
            byte[] result = cipher.doFinal(byteContent);
            return result; // 加密
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
        } catch (InvalidKeyException e) {
            e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (IllegalBlockSizeException e) {
            e.printStackTrace();
        } catch (BadPaddingException e) {
            e.printStackTrace();
        }
        return null;
    }

    /**解密
     * @param content  待解密内容
     * @param password 解密密钥
     * @return
     */
    public static String sampleDecrypt(String content, String password) {
        byte[] result =decrypt(SecretUtil.parseHexStr2Byte(content),password);
        return SecretUtil.parseByte2HexStr(result);
    }


        /**解密
         * 加密后的byte数组是不能强制转换成字符串的，字符串和byte数组在这种情况下不是互逆的
         * 要避免这种情况，我们需要做一些修订，可以考虑将二进制数据转换成十六进制表示，主要有如下两个方法
         * @param content  待解密内容
         * @param password 解密密钥
         * @return
         */
    public static byte[] decrypt(byte[] content, String password) {
        try {
            KeyGenerator kgen = KeyGenerator.getInstance("AES");
            kgen.init(128, new SecureRandom(password.getBytes()));
            SecretKey secretKey = kgen.generateKey();
            byte[] enCodeFormat = secretKey.getEncoded();
            SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
            Cipher cipher = Cipher.getInstance("AES");// 创建密码器
            cipher.init(Cipher.DECRYPT_MODE, key);// 初始化
            byte[] result = cipher.doFinal(content);
            return result; // 加密
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
        } catch (InvalidKeyException e) {
            e.printStackTrace();
        } catch (IllegalBlockSizeException e) {
            e.printStackTrace();
        } catch (BadPaddingException e) {
            e.printStackTrace();
        }
        return null;
    }


    /**将16进制转换为二进制
     * @param hexStr
     * @return
     */
    public static byte[] parseHexStr2Byte(String hexStr) {
        if (hexStr.length() < 1)
            return null;
        byte[] result = new byte[hexStr.length()/2];
        for (int i = 0;i< hexStr.length()/2; i++) {
            int high = Integer.parseInt(hexStr.substring(i*2, i*2+1), 16);
            int low = Integer.parseInt(hexStr.substring(i*2+1, i*2+2), 16);
            result[i] = (byte) (high * 16 + low);
        }
        return result;
    }

    /**将二进制转换成16进制
     * @param buf
     * @return
     */
    public static String parseByte2HexStr(byte buf[]) {
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < buf.length; i++) {
            String hex = Integer.toHexString(buf[i] & 0xFF);
            if (hex.length() == 1) {
                hex = '0' + hex;
            }
            sb.append(hex.toUpperCase());
        }
        return sb.toString();
    }






    public static String encryptF(String data, String key) {
        try {
            Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
            SecretKeySpec keyspec = new SecretKeySpec(key.getBytes(), "AES");
            cipher.init(Cipher.ENCRYPT_MODE, keyspec);
            byte[] encrypted = cipher.doFinal(data.getBytes());
            return Base64.encodeToString(encrypted, Base64.DEFAULT);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    public static String desEncryptF(String data, String key)  {
        try {
            byte[] encrypted1 = Base64.decode(data.getBytes(), Base64.DEFAULT);
            Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
            SecretKeySpec keyspec = new SecretKeySpec(key.getBytes(), "AES");
            cipher.init(Cipher.DECRYPT_MODE, keyspec);
            byte[] original = cipher.doFinal(encrypted1);
            return new String(original, "UTF-8");
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }



    public static String  Test2(){
        String content = "test";
        String password = "12345678";
//加密
        String encryptResultStr = encryptF(content,password);
        System.out.println("加密后：" + encryptResultStr);
//解密
        String  decryptResult = desEncryptF(encryptResultStr,password);
        System.out.println("解密后：" + new String(decryptResult));
        return "加密后：" + encryptResultStr+"|解密后：" + decryptResult;
    }


    public static String  Test(){
        String content = "test";
        String password = "12345678";
//加密
        System.out.println("加密前：" + content);
        byte[] encryptResult = encrypt(content, password);
        String encryptResultStr = parseByte2HexStr(encryptResult);
        System.out.println("加密后：" + encryptResultStr);
//解密
        byte[] decryptFrom = parseHexStr2Byte(encryptResultStr);
        byte[] decryptResult = decrypt(decryptFrom,password);
        System.out.println("解密后：" + new String(decryptResult));
        return "加密前：" + content+"|加密后：" + encryptResultStr+"|解密后：" + new String(decryptResult);
    }



}
